This Phase II application proposes to continue development of the ASI-MV-CAT, a Computer Adaptive Testing edition of Inflexxion's popular Addiction Severity Index-Multimedia Version (ASI-MV). Built on the ASI, probably the most widely used adult assessment for substance use problems in the US, the ASI-MV provides a reliable, valid and cost-effective version for all clinical and research purposes. The Internet connectivity of ASI-MV Connect allows automated collection of data in a manner that is compatible with clinical and administrative systems. The ASI-MV is currently used at more than 500 sites throughout the country and is administered nearly a hundred thousand individuals annually. Despite its substantial commercial success, the current version of the ASI-MV suffers from some of the psychometric problems inherent in the ASI itself. Developed more than quarter century ago, concerns have mounted about the psychometric performance of the ASI, particularly as evaluated in light of modern thinking. Furthermore, profound changes in the nature of the substances abused, patient populations, and treatments have occurred during the past 25 years. Thus, the ASI and, by extension, the ASI-MV do not meet all critical assessment and treatment needs of administrators, researchers, and clinicians. The ASI-MV-CAT is intended to update the ASI and to provide the option for brief, but state-of-the-art, assessment. The ASI-MV has amply demonstrated the feasibility of using computer- mediated administration of the ASI. Based on principles of Item Response Theory (IRT), a computer adaptive testing (CAT) version of the ASI-MV will permit improvement in several, related measurement concepts: (1) scaling and dimensionality of derived scores, (2) interval measurement of clients' problem severity, (3) overall adherence to scientific measurement principles and hence, (4) applicability of measurement data to statistical analyses. CAT also permits a quick ASI screening or follow-up assessment that could potentially reduce administration time 50% to 80%. In Phase I, the Specific Aims were accomplished utilizing a large database of ASI-MV Connect assessments (N = 23,400). A comprehensive examination of the psychometric (classical test theory-CTT and IRT) status of the existing ASI items for all ASI domains was conducted. While some domain items performed better than others, each domain was found to require updating and improvement. Two pools of potential new items were generated for the employment and psychiatric domains. Phase II will see the completion of four Specific Aims: (1) development and qualitative evaluation of new pools of items for the remaining ASI domains (medical, alcohol, drug, legal, and family/social), (2) comprehensive psychometric analyses of the entire item bank on a large number of clients in treatment for substance use disorders and a community, non-clinical sample, (3) creation of a fully functioning prototype of an ASI-MV-CAT, and (4) empirical tests of validity and sensitivity to change of the ASI-MV-CAT. These steps will result in a new and more powerful version of the ASI that will represent a significant advance in the evolution of this important tool. PUBLIC HEALTH RELEVANCE: The ASI is the gold standard assessment for individuals in substance abuse treatment. Since its creation, changes in the substances abused, patient populations, treatments, and psychometric standards suggest the need for an updated version. The proposed ASI-MV-CAT would address this need and permit flexible and efficient administration options, updated content, and could be rapidly disseminated. The ASI-MV-CAT will have major public health importance and significant commercial potential.